A new type of personalized cancer therapy in which immune cells are harvested from patients' tumors, grown in the lab and infused back into patients showed dramatic results in a small, government-led trial in women with advanced cervical cancer, U.S. researches found.
Two out of the nine women in the study who had cervical cancer tumors that had spread throughout their bodies had a complete remission of their cancers after a single treatment, and remained cancer free more than a year later, according to the study, which was presented at the American Society of Clinical Oncology's (ASCO) annual meeting in Chicago on Monday. That's far better than any other treatment has achieved in such cases.
The trial by researchers at the National Cancer Institute is the first to show that this promising new technology, known as adoptive T cell therapy, can have an impact in solid tumors, said Dr. Renier Brentjens, director of cellular therapeutics at Memorial Sloan Kettering Cancer Center, who was not involved in the study.
The approach attempts to take advantage of the body's own T cells — infection-fighting white blood cells that recognize and mount an attack on harmful invaders such as viruses and cancer. Researchers at Memorial Sloan Kettering have already shown dramatic results in blood cancers such as acute lymphoblastic leukemia.
"This is yet another example of a successful application of adoptive T cell immunotherapy, now in the realm of solid tumors, such as cervical cancers," Brentjens told Reuters. "We're starting to see that T cells, if properly targeted, can eradicate incurable metastatic cancers."
In this early-stage trial, researchers studied nine women with metastatic cervical cancer caused by the human papillomavirus (HPV) in whom there are currently few treatment options.
For the therapy, researchers essentially beefed up the patients' own weak immune responses to the cancer by removing T cells from their tumors that recognize two HPV-related proteins. The team then grew up batches of these HPV-targeting immune cells and returned them to the patients to fight the cancer.
Of the nine women tested, three responded. One had a partial response in which the tumor shrank by nearly 40 percent, a response that lasted for three months. Two patients have had complete remission of their cancers that so far has lasted for 15 months in one patient and 22 months in the other.
"What this means is on a very specific level … patients that have otherwise metastatic cervical cancer now have a treatment option that may in about a third of cases provide them with durable disease response," Brentjens said.
Tinkering with the immune system in this way caused some serious side effects, however, including low blood counts and infections, but the findings are promising enough to expand the trial to more patients, the team said.
Study leader Dr. Christian Hinrichs of the National Cancer Institute said at the ASCO meeting that the government plans to expand this study to 35 women with advanced cervical cancer. It could someday be offered at many cancer centers the way bone marrow and stem cell transplants are now.
Currently, the study is only going on at the National Cancer Institute, and researchers at the ASCO meeting acknowledged that the labor-intensive technology may be difficult to scale up at non-academic centers.
Immune therapy struggled for years with just occasional small gains, but "now we have cruise missiles" giving better kill rates against many tumor types, Dr. Steven O'Day of the University of Southern California told the Associated Press.
Others tempered their enthusiasm, noting that some promising approaches produced more limited gains once they were more fully researched.
"Let's not forget the history" of what seems like progress with a new approach, Dr. Len Lichtenfeld, deputy chief medical officer of the American Cancer Society, told the AP. "It doesn't always work out the way it appears to be heading."